Prediction of post-intervention fractional flow reserve in diffuse or sequential coronary stenosis considering the residual trans-stent pressure gradient: Post-intervention FFR in diffuse/sequential lesions.

Abstract

Prediction of post-intervention fractional flow reserve (FFR) in a diffuse or sequential coronary lesion is difficult due to complex haemodynamic interactions between individual stenoses. Furthermore, the existence of a residual intra-stent pressure gradient makes the prediction difficult. We developed an equation predicting the post-intervention FFR in a diffuse/sequential lesion by considering intra-stent FFR gradient. The present study aims to validate the equation in an in vitro model and in clinical data. In the in vitro experiment, three sequential coronary stenoses were made with a collateral flow. The correlation coefficient of the predicted FFR and the actual post-intervention FFR was 0.99, and the absolute difference was 0.008±0.006 (n=50). In the clinical data analysis, the correlation coefficient was 0.41, and the absolute difference was 0.06±0.05 (n=67). We applied a fixed value of intra-stent FFR gradient and a collateral flow index so that the equation can be used in clinical practice. The correlation coefficient became 0.28 and the absolute difference became 0.06±0.06. In clinical practice, prediction of post-intervention FFR in a diffuse/sequential lesion is difficult even when residual intra-stent pressure gradient is considered.